1.Its time（for sb.）to do sth./Its time for sth.

譯為“是（某人）該干……的時(shí)間了”、“到……的時(shí)候了”。如：

Its time for supper /to have supper.

2.It takes（sb.）some time to do sth.

譯為“（某人）花……時(shí)間做某事”。如：

It took me a week to finish reading the book.

3.It is ones turn to do sth.

表示“輪到某人做某事”。如：

Its your turn to be on duty tomorrow.

4.It is /has been +時(shí)間段+since +一般過去時(shí)。

譯為“自從……以來已過了……（時(shí)間）”。

此結(jié)構(gòu)可以與另一種句型進(jìn)行同義句轉(zhuǎn)換。如：

It has been two weeks since we met last.

=Two weeks has passed since we met last.

5.It seems /seemed +that從句。

譯為“看起來好像……”，此結(jié)構(gòu)可以轉(zhuǎn)換成“seem +不定式”形式。如：

It seems that he is ill.

=He seems to be ill.

6.Its+adj.+of/forsb.+不定式。

這里再強(qiáng)調(diào)一下：如果形容詞是描述不定式行為者的性格、品質(zhì)的，如：kind，good，nice，clever等用of；如果僅僅是描述事物的形容詞，如：difficult，easy，hard， important，dangerous等則用for。如：

It was very kind of you to visit me when I was ill.

Its important for him to learn English well.

7.Its+表語 +to do sth.。如：

Its a good idea to go out for a walk.

=To go out for a walk is a good idea.

8.Its+adj.+ that從句。如：

Its true that he may fall behind the other students.